• 제목/요약/키워드: eigenvectors

검색결과 240건 처리시간 0.021초

비선형 특징 추출을 위한 온라인 비선형 주성분분석 기법 (On-line Nonlinear Principal Component Analysis for Nonlinear Feature Extraction)

  • 김병주;심주용;황창하;김일곤
    • 한국정보과학회논문지:소프트웨어및응용
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    • 제31권3호
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    • pp.361-368
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    • 2004
  • 본 논문에서는 온라인 학습 자료의 비선형 특징(feature) 추출을 위한 새로운 온라인 비선형 주성분분석(OL-NPCA : On-line Nonlinear Principal Component Analysis) 기법을 제안한다. 비선형 특징 추출을 위한 대표적인 방법으로 커널 주성분방법(Kernel PCA)이 사용되고 있는데 기존의 커널 주성분 분석 방법은 다음과 같은 단점이 있다. 첫째 커널 주성분 분석 방법을 N 개의 학습 자료에 적용할 때 N${\times}$N크기의 커널 행렬의 저장 및 고유벡터를 계산하여야 하는데, N의 크기가 큰 경우에는 수행에 문제가 된다. 두 번째 문제는 새로운 학습 자료의 추가에 의한 고유공간을 새로 계산해야 하는 단점이 있다. OL-NPCA는 이러한 문제점들을 점진적인 고유공간 갱신 기법과 특징 사상 함수에 의해 해결하였다. Toy 데이타와 대용량 데이타에 대한 실험을 통해 OL-NPCA는 다음과 같은 장점을 나타낸다. 첫째 메모리 요구량에 있어 기존의 커널 주성분분석 방법에 비해 상당히 효율적이다. 두 번째 수행 성능에 있어 커널 주성분 분석과 유사한 성능을 나타내었다. 또한 제안된 OL-NPCA 방법은 재학습에 의해 쉽게 성능이 항상 되는 장점을 가지고 있다.

Eigen - Environment 잡음 보상 방법을 이용한 강인한 음성인식 (Robust Speech Recognition using Noise Compensation Method Based on Eigen - Environment)

  • 송화전;김형순
    • 대한음성학회지:말소리
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    • 제52호
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    • pp.145-160
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    • 2004
  • In this paper, a new noise compensation method based on the eigenvoice framework in feature space is proposed to reduce the mismatch between training and testing environments. The difference between clean and noisy environments is represented by the linear combination of K eigenvectors that represent the variation among environments. In the proposed method, the performance improvement of speech recognition systems is largely affected by how to construct the noisy models and the bias vector set. In this paper, two methods, the one based on MAP adaptation method and the other using stereo DB, are proposed to construct the noisy models. In experiments using Aurora 2 DB, we obtained 44.86% relative improvement with eigen-environment method in comparison with baseline system. Especially, in clean condition training mode, our proposed method yielded 66.74% relative improvement, which is better performance than several methods previously proposed in Aurora project.

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Eigenstructure Assignment Considering Probability of Instability with Flight Control Application

  • Seo, Young-Bong;Choi, Jae-Weon
    • International Journal of Control, Automation, and Systems
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    • 제5권6호
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    • pp.607-613
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    • 2007
  • Eigenstructure assignment provides the advantage of allowing great flexibility in shaping the closed-loop system responses by allowing specification of closed-loop eigenvalues and corresponding eigenvectors. But, the general eigenstructure assignment methodologies cannot guarantee stability robustness to parameter variations of a system. In this paper, we present a novel method that has the capability of exact assignment of an eigenstructure which can consider the probability of instability for LTI (Linear Time-Invariant) systems. The probability of instability of an LTI system is determined by the probability distributions of the closed-loop eigenvalues. The stability region for the system is made probabilistically based upon the Monte Carlo evaluations. The proposed control design method is applied to design a flight control system with probabilistic parameter variations to confirm the usefulness of the method.

유전자 알고리즘과 퍼지규칙을 기반으로한 지능형 자동감시 시스템의 개발 (A Fuzzy Logic System for Detection and Recognition of Human in the Automatic Surveillance System)

  • 장석윤;박민식;이영주;박민용
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2001년도 하계종합학술대회 논문집(3)
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    • pp.237-240
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    • 2001
  • An image processing and decision making method for the Automatic Surveillance System is proposed. The aim of our Automatic Surveillance System is to detect a moving object and make a decision on whether it is human or not. Various object features such as the ratio of the width and the length of the moving object, the distance dispersion between the principal axis and the object contour, the eigenvectors, the symmetric axes, and the areas if the segmented region are used in this paper. These features are not the unique and decisive characteristics for representing human Also, due to the outdoor image property, the object feature information is unavoidably vague and inaccurate. In order to make an efficient decision from the information, we use a fuzzy rules base system ai an approximate reasoning method. The fuzzy rules, combining various object features, are able to describe the conditions for making an intelligent decision. The fuzzy rule base system is initially constructed by heuristic approach and then, trained and tasted with input/output data Experimental result are shown, demonstrating the validity of our system.

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2-TYPE HYPERSURFACES SATISFYING ⟨Δx, x - x0⟩ = const.

  • Jang, Changrim
    • East Asian mathematical journal
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    • 제34권5호
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    • pp.643-649
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    • 2018
  • Let M be a connected n-dimensional submanifold of a Euclidean space $E^{n+k}$ equipped with the induced metric and ${\Delta}$ its Laplacian. If the position vector x of M is decomposed as a sum of three vectors $x=x_1+x_2+x_0$ where two vectors $x_1$ and $x_2$ are non-constant eigenvectors of the Laplacian, i.e., ${\Delta}x_i={\lambda}_ix_i$, i = 1, 2 (${\lambda}_i{\in}R$) and $x_0$ is a constant vector, then, M is called a 2-type submanifold. In this paper we proved that a connected 2-type hypersurface M in $E^{n+1}$ whose postion vector x satisfies ${\langle}{\Delta}x,x-x_0{\rangle}=c$ for a constant c, where ${\langle}$, ${\rangle}$ is the usual inner product in $E^{n+1}$, is of null 2-type and has constant mean curvature and scalar curvature.

동특성 변화로부터 구조물의 변경된 설계파라미터 해석 (Analysis of Design Parameter of Structural Modification using Change of Dynamic Characteristics)

  • 오재응;이정우;이정윤
    • 대한기계학회논문집A
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    • 제30권4호
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    • pp.387-392
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    • 2006
  • This paper predicts the modified mass and stiffness of structure using the sensitivity coefficients with the iterative method. The sensitivity coefficients are obtained by the change of the eigenvectors according to structural modification. The method is applied to an examples of a 3 degree of freedom system by modifying mass and stiffness. The predicted mass and stiffness are in good agreement with these from the structural reanalysis using the modified mass and stiffness.

감도계수 반복법을 이용한 비비례감쇠계의 고유치 및 고유벡터 변화량 해석 (Analysis of Eigenderivative for the Non-Proportional Damped Structure Using the Iterative Method of the Sensitivity Coefficient)

  • 이정윤
    • 대한기계학회논문집A
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    • 제30권7호
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    • pp.750-756
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    • 2006
  • This study predicts the modified eigenvectors and eigenvalues of the non-proportional damped structure due to the change in the mass, damping and stiffness of structure by iterative method of the sensitivity coefficient using the original dynamic characteristic. The method is applied to the non-proportional damped 3 degree of freedom system by modifying the mass, damping and stiffness. The predicted dynamic characteristics are showed a good agreement with these from the structural reanalysis using the modified mass, damping and stiffness.

근사모드법을 이용한 철근콘크리트 구조물의 비선형해석 (Nonlinear Dynamic Anslysis of R/C Structures Using Approximate Modal Approach)

  • 장극관;이리형
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1994년도 봄 학술발표회 논문집
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    • pp.77-84
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    • 1994
  • An approximate method of normal coordinate idealization for use in nonlinear R/C frames has been developed. Normal coordinate apporaches have been used for nonlinear problems in the past, but they are not received wide acceptance because of the need for eigenvector computation in each time step. The proposed method cicumvents the eigenvector recalculation problem by evaluating a limited number of sets of mode shapes in performing the dynamic analysis. Then the predetermined sets of eigenvectors are used in the nonlinear dynamic analysis, repeatedly. The method is applied to frame structures with ductiles R/C elements. The plastic hinge zones are modeled with hysteresis loops which evince degrading stiffness and pinching effects. The method is applied to frames with local nonlinearities. Efficiencies and accuracies of the method for this application are presented.

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보조변수법을 이용한 감쇠계 고유치 설계민감도 해석 (Adjoint Design Sensitivity Analysis of Damped Systems)

  • 유정훈;이태희
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 춘계학술대회논문집C
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    • pp.398-401
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    • 2001
  • There are two methods to calculate design sensitivity such as direct differentiation method and adjoint method. A sort of direct differentiation method for design sensitivity analysis costs too much when number of design variables is much larger than the number of response functions whose design sensitivity analyses are required. Therefore, an adjoint method is suggested for the case that the dimension of design variables is lager than the number of response function. An adjoint method is required to compute adjoint variables from the simultaneous linear system equation, the so-called adjoint equation, requiring only the eigenvalue and its associated eigenvectors for mode being differentiated. This method has been extended to the repeated eigenvalue problem. In this paper, we propose an adjoint method for deign sensitivity analysis of damped vibratory systems with distinct eigenvalues.

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모달 파라미터를 이용한 보 구조물의 모델링 (Modeling of Beam Structures from Modal Parameters)

  • 황우석
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2006년도 추계학술대회논문집
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    • pp.519-522
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    • 2006
  • Accurate modeling of a dynamic system from experimental data is the bases for the model updating or heath monitoring of the system. Modal analysis or modal test is a routine process to get the modal parameters of a dynamic system. The modal parameters include the natural frequencies, damping ratios and mode shapes. This paper presents a new method that can derive the equations of motion for a dynamic system from the modal parameters obtained by the modal analysis or modal test. The present method based on the relation between the eigenvalues and eigenvectors of the state space equation derives the mass, damping and stiffness matrices of the system. The modeling of a cantilevered beam from modal parameters is an example to prove the efficiency and accuracy of the present method. Using the lateral displacements only, not the rotations, gives limited information for the system. The numerical verification up to now gives reasonable results and the verification with the test data is scheduled.

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